Genetic alterations increase the risk of a number of diseases. A study has found, however, that the type of lifestyles led by families may play a more important role than genes in affecting risk.

Most diseases that cause major health complications in the adult population are the result of the interaction of many genes and lifestyle factors.

Studies that target the genetic causes of disease use large numbers of people and gene sequencing data sets to create a map of gene areas that increase or decrease disease risk.

This approach, known as genome-wide association studies (GWAS), has found many genetic changes that can cause disease risk.

Despite the millions of dollars invested in gene sequencing technology, the extent to which genetic alterations can explain the risks of adult diseases is very small. The missing variable in these genetic studies is how people live their lives, as well as the shared environment.

Most people in the developed world live in small family groups (the nuclear family) that interact with larger groups of related family members including uncles, aunties and cousins, often only a few times a year.

Despite the relatively infrequent interaction, lifestyle factors including cuisine and cultural habits (like religion), financial status, alcohol and smoking rates are far stronger between members of extended families than between unrelated family groups.

Researchers in the UK have examined the complementary role of genes and lifestyle for the risk of most major adult diseases. This study included the GWAS analysis of disease risk in just over one and a half million people.

When the connections between families and their lifestyles were factored into the equation, the impact of genes was overestimated by almost 50%. The study highlighted the many gaps in understanding how people and families interact to impact on the risks of serious diseases, such as heart disease and diabetes.

Implications

Whilst genetic discoveries help identify those at increased risk of many diseases, it is too easy to forget that the way we live and who we live with is possibly more important than genes.

Healthy food, enough exercise and stress management are three lifestyle factors that are most important for you and your extended family.

Last Reviewed: 16/10/2019

© Norman Swan Medical Communications.



References

Munoz M at al. Evaluating the contribution of genetics and familial hared environment to common disease using the UK Biobank. Nature Genetics Epub online July 18, 2016. doi: 10.1038/ng.3618.